In the related art, in the case where the SW PEC or ISAM PEC operates erroneously, or a foreign substance or human body is sandwiched between wirings through which high voltage is supplied, a fuse primarily cuts off the high voltage. However, if a load that does not exceed a limit value of the fuse is applied, the ESS is unable to recognize this, and thus the high voltage is continuously supplied to cause fire or trouble of the equipment to occur.